Originally posted by DaPi
But it's not! It's just one of many "tools" that you can use to judge if your db is healthy - you need to understand its usefulness and its limitations in the context of your db.

Ok, lets see how use full might be that * HIT Ratio *..

Case 1 :

Ratio > 95+

* Some argue that u gotta bad sqls where in ur LIOs shooting up so much that u cannot see the PIOs to be significant..

* But it can as well be some thing like ALL SQL perfectly tuned and ther isnt any crap requirement by which LIOs will have shoot up ... and yes now u can say HIT is perfect and u can be happy..

So with this u really cannot make anything unless u know what SQL are running and r they tuned and so many with respect to SQL.

Case 2 :

Ratio < 75-

* Some may argue that u have a balance between PIO/LIO and assume all SQL tuned one.

* Contradictory to it will be, there are very simple requirements (SQLs) and its codeded in such a fashion its worst ( BAD sqls ) and ofen reading data from files...


So with this as well u really cannot make anything unless u know what SQL are running and r they tuned and so many with respect to SQL.


So, why bother on HIT Ratio and just start looking for BAD SQLs and every one will be happy !

Abhay.